1. Field
The present disclosure relates to the field of information technologies, and in particular to a flicker detection apparatus and method.
2. Description of the Related Art
In recent years, CMOS (complementary metal oxide semiconductor) image sensor has been used in image capture devices broadly, such as a digital camera, a digital video camera, and a smart mobile phone, etc. Because the timing of photoelectric conversion is different for each pixel or each row of pixels in the process of photoelectric conversion, bright-dark horizontal stripes exist in captured images, when image capture is performed under fluorescent lamp illumination or under some other illumination conditions where the brightness changes periodically. And such horizontal stripes generated by periodical changes of the illumination light in captured images are called “flickers”.
To suppress such flickers, the exposure time should be set according to the flicker frequency. So the detection of whether flickers exist in an image and a flicker frequency is a significant issue.
In existing flicker detection methods, some use a light detector to detect light signals, and detect flickers by using calculation results of square waves with different frequencies and detected light signals. And some divide the columns of a frame image into several portions, calculate the average values of each column portion in each row, and use square waves with different frequencies for calculating average value vectors for each column portion, to detect the flickers by comparing calculation results.
It should be noted that the above description of the background is merely provided for clear and complete explanation of the present disclosure and for easy understanding by those skilled in the art. And it should not be understood that the above technical solution is known to those skilled in the art as it is described in the background of the present disclosure.